Write tcp, write broken pipe

Hello,

since the upgrade of grafana to 7.3.5 we have encountered “broken pipe” problems.
The dashboards all put in error after a few hours of use, as seen below.
image
Grafana is linked to a postgresql 10 database.
A restart of the grafana services makes it possible to solve it, for x time but this solution is not viable.

Do you have an idea ?
thanks in advance